U.S. patent application number 13/757651 was filed with the patent office on 2014-05-01 for mobile device and optical imaging lens.
This patent application is currently assigned to Genius Electronic Optical Co., Ltd.. The applicant listed for this patent is GENIUS ELECTRONIC OPTICAL CO., LTD.. Invention is credited to Kuo-Wen Chang, Poche Lee, Wei-Yu Lo.
Application Number | 20140118613 13/757651 |
Document ID | / |
Family ID | 48871871 |
Filed Date | 2014-05-01 |
United States Patent
Application |
20140118613 |
Kind Code |
A1 |
Chang; Kuo-Wen ; et
al. |
May 1, 2014 |
MOBILE DEVICE AND OPTICAL IMAGING LENS
Abstract
An optical imaging lens includes first, second, third, fourth
and fifth lens elements positioned sequentially from an object side
to an image side. The first lens element with positive refractive
power has an object-side surface comprising a convex portion in the
optical axis vicinity. The second lens element with negative
refractive power has an object-side surface comprising a convex
portion in the optical axis vicinity and an image-side surface
comprising a concave portion in the optical axis vicinity. The
third lens element has an image-side surface comprising a convex
portion in the periphery. The fourth lens element has an image-side
surface comprising a convex portion in the optical axis vicinity.
The fifth lens element has an object-side surface comprising a
convex portion in the optical axis vicinity and an image-side
surface comprising a concave portion in the optical axis vicinity
and a convex portion in the periphery.
Inventors: |
Chang; Kuo-Wen; (Taichung
City, TW) ; Lee; Poche; (Taichung City, TW) ;
Lo; Wei-Yu; (Taichung City, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
GENIUS ELECTRONIC OPTICAL CO., LTD. |
Taichung City |
|
TW |
|
|
Assignee: |
Genius Electronic Optical Co.,
Ltd.
Taichung City
TW
|
Family ID: |
48871871 |
Appl. No.: |
13/757651 |
Filed: |
February 1, 2013 |
Current U.S.
Class: |
348/374 ;
359/764 |
Current CPC
Class: |
G02B 13/0045 20130101;
G02B 9/60 20130101; H04N 5/2254 20130101 |
Class at
Publication: |
348/374 ;
359/764 |
International
Class: |
G02B 9/60 20060101
G02B009/60; H04N 5/225 20060101 H04N005/225 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 31, 2012 |
TW |
101140376 |
Claims
1. An optical imaging lens, sequentially from an object side to an
image side, comprising first, second, third, fourth and fifth lens
elements, each of said first, second, third, fourth and fifth lens
elements having an object-side surface facing toward the object
side and an image-side surface facing toward the image side,
wherein: said first lens element has positive refractive power, and
said object-side surface thereof comprises a convex portion in a
vicinity of the optical axis; said second lens element has negative
refractive power, said object-side surface thereof comprises a
convex portion in vicinity of the optical axis, and said image-side
surface thereof comprises a concave portion in a vicinity of the
optical axis; said image-side surface of said third lens element
comprises a convex portion in a vicinity of a periphery of the
third lens element; said image-side surface of said fourth lens
element comprises a convex portion in a vicinity of the optical
axis; said object-side surface of said fifth lens element comprises
a convex portion in a vicinity of the optical axis, and said
image-side surface of said fifth lens element comprises a concave
portion in a vicinity of the optical axis and a convex portion in a
vicinity of a periphery of the fifth lens element; and said optical
imaging lens as a whole having only the five lens elements having
refractive power, wherein the sum of the thickness of all five lens
elements along the optical axis is defined as ALT, the central
thickness of the first lens element along the optical axis is
T.sub.1, and ALT and T.sub.1 satisfy the equation: ALT T 1 .ltoreq.
4. ##EQU00090##
2. The optical imaging lens according to claim 1, wherein the sum
of all air gaps from the first lens element to the fifth lens
element along the optical axis is G.sub.aa, an air gap between the
first lens element and the second lens element along the optical
axis is G.sub.12, an air gap between the fourth lens element and
the fifth lens element along the optical axis is G.sub.45, and
G.sub.aa, G.sub.12 and G.sub.45 satisfy the equations: 11.5
.ltoreq. G aa G 12 ; and ##EQU00091## G 45 G 12 .ltoreq. 5.5 .
##EQU00091.2##
3. The optical imaging lens according to claim 2, further
comprising an aperture stop positioned at the object side of the
first lens element.
4. The optical imaging lens according to claim 3, the focal length
of the third lens element is f3, the effective focal length of the
optical imaging lens is f, and f3 and f satisfy the equation: 0
< f 3 f . ##EQU00092##
5. The optical imaging lens according to claim 4, wherein Gaa and
T1 satisfy the equation: G aa T 1 .ltoreq. 2.0 . ##EQU00093##
6. The optical imaging lens according to claim 5, wherein T.sub.1
and G.sub.12 satisfy the equation: 6 .ltoreq. T 1 G 12 .
##EQU00094##
7. The optical imaging lens according to claim 4, wherein G.sub.aa
satisfies the equation: G.sub.aa.ltoreq.1.3 mm.
8. The optical imaging lens according to claim 7, wherein G.sub.aa,
ALT and G.sub.12 satisfy the equation: 5 mm - 1 .ltoreq. G aa ALT
.times. G 12 . ##EQU00095##
9. The optical imaging lens according to claim 8, wherein T.sub.1
and G.sub.12 satisfy the equation: 9.5 .ltoreq. T 1 G 12 .
##EQU00096##
10. The optical imaging lens according to claim 8, wherein
G.sub.aa, ALT and G.sub.12 further satisfy the equation: 8 mm - 1
.ltoreq. G aa ALT .times. G 12 . ##EQU00097##
11. The optical imaging lens according to claim 4, wherein Gaa, G12
and G45 satisfy the equation: G aa G 12 + G 45 .ltoreq. 5.5 .
##EQU00098##
12. The optical imaging lens according to claim 11, wherein
G.sub.aa satisfies the equation: G.sub.aa.ltoreq.1.3 mm.
13. The optical imaging lens according to claim 12, wherein
G.sub.aa, ALT and G.sub.12 further satisfy the equation: 6.5 mm - 1
.ltoreq. G aa ALT .times. G 12 . ##EQU00099##
14. The optical imaging lens according to claim 11, wherein T.sub.1
and G.sub.12 satisfy the equation: 6 .ltoreq. T 1 G 12 .
##EQU00100##
15. A mobile device, comprising: a housing; and an image module
positioned in the housing and comprising: a lens barrel; an optical
imaging lens as claimed in claim 1 and positioned in the barrel; a
module housing unit for positioning the lens barrel; and an image
sensor positioned at the image side of the optical imaging
lens.
16. The mobile device according to claim 15, wherein the module
housing unit further comprises an a first lens seat and a second
lens seat, the first lens seat is positioned close to the outside
of the lens barrel and along with an axis, the second lens seat is
positioned along the axis and around the outside of the first lens
seat, and the lens barrel and the optical imaging lens positioned
therein are driven by the first lens seat to move along the
axis.
17. The mobile device according to claim 16, wherein the module
housing unit further comprises an image sensor backseat positioned
between the second lens seat and the image sensor, and close to the
second lens seat.
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application claims priority to Taiwan Patent
Application No. 101140376, filed on Oct. 31, 2012, the content of
which is hereby incorporated by reference in its entirety for all
purposes.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a mobile device and an
optical imaging lens thereof, and particularly, relates to a mobile
device applying an optical imaging lens having five lens elements
and an optical imaging lens thereof.
[0003] The ever-increasing demand for smaller sized mobile devices,
such as cell phones, digital cameras, etc. has correspondingly
triggered a growing need for smaller sized photography modules
contained therein. Size reductions may be contributed from various
aspects of the mobile devices, which includes not only the charge
coupled device (CCD) and the complementary metal-oxide
semiconductor (CMOS), but also the optical imaging lens mounted
therein. When reducing the size of the optical imaging lens,
however, achieving good optical characteristics becomes a
challenging problem.
[0004] US Patent Publication No. 2011176049, US Patent Publication
No. 20110316969, and U.S. Pat. No. 7,480,105 all disclosed an
optical imaging lens constructed with an optical imaging lens
having five lens elements, in which the first lens element has
negative refractive power, which is difficult to reduce the length
of the optical imaging lens and maintain good optical
characteristics.
[0005] US Patent Publication No. 20120069455, US Patent Publication
No. 20100254029, TW Patent No. M369459, and JP Patent Publication
No. 2010-224521 all disclosed an optical imaging lens constructed
with an optical imaging lens having five lens elements, in which
the portion of embodiments have excessive sum of all air gaps
between the lens elements along the optical axis, which is
unfavorable for endeavoring slimmer mobile devices, such as cell
phones and digital cameras.
[0006] US Patent Publication No. 20120087019, US Patent Publication
No. 20120087020, US Patent Publication No. 20120105704, and U.S.
Pat. No. 8,179,614 all disclosed an optical image lens constructed
with an optical imaging lens having five lens elements, in which
the portion of embodiments have excessive air gap between the first
lens element and the second lens element, which is unfavorable for
endeavoring slimmer mobile devices, such as cell phones and digital
cameras.
[0007] US Patent Publication No. 20100253829, and TW Patent
Publication No. 2012013926 all disclosed an optical image lens
constructed with an optical image lens having five lens elements,
in which the total thickness of the five lens elements is
excessive, which is unfavorable for endeavoring slimmer mobile
devices, such as cell phones and digital cameras.
[0008] Especially, in US Patent Publication No. 20100254029, the
length of the optical imaging lens is over 9.7 mm, which is not
beneficial for the slimmer and smaller design of mobile
devices.
[0009] Shortening the length of an optical imaging lens is one of
the most important topics in the industry to pursue the trend of
smaller and smaller mobile devices. Therefore, there is a need for
an optical imaging lens having a shorter length and good optical
characteristics.
BRIEF SUMMARY OF THE INVENTION
[0010] An object of the present invention is to provide a mobile
device and an optical imaging lens thereof. By controlling the
convex or concave shape of the surfaces of the lens elements, the
length of the optical imaging lens can be shortened while
sustaining good optical characteristics, such as high resolution
and others.
[0011] In an exemplary embodiment, an optical imaging lens,
sequentially from an object side to an image side, comprises first,
second, third, fourth and fifth lens elements, each of the first,
second, third, fourth, and fifth lens elements having an
object-side surface facing toward the object side and an image-side
surface facing toward the image side. The first lens element has
positive refractive power, and the object-side surface thereof
comprises a convex portion in a vicinity of an optical axis. The
second lens element has negative refractive power, the object-side
surface thereof comprises a convex portion in a vicinity of the
optical axis, and said image-side surface thereof comprises a
concave portion in a vicinity of the optical axis. The image-side
surface of the third lens element comprises a convex portion in a
vicinity of a periphery of the third lens element. The image-side
surface of the fourth lens element comprises a convex portion in a
vicinity of the optical axis; and the object-side surface of said
fifth lens element comprises a convex portion in a vicinity of the
optical axis, and the image-side surface of the fifth lens element
comprises a concave portion in a vicinity of the optical axis and a
convex portion in a vicinity of a periphery of the fifth lens
element. The optical imaging lens as a whole comprising the five
lens elements has refractive power, wherein the sum of the
thickness of all five lens elements along the optical axis is
referred to as "ALT," a central thickness of the first lens element
along the optical axis is referred to as "T.sub.1", and they
satisfy the relation:
ALT T 1 .ltoreq. 4. ##EQU00001##
[0012] In another exemplary embodiment, other parameters of the
optical imaging lens, such as the relations of the sum of all air
gaps between the lens elements along the optical axis and each air
gap between two adjacent lens elements along the optical axis, can
be controlled. An example among them is controlling the sum of all
air gaps from the first lens element to the fifth lens element
along the optical axis, G.sub.aa, and an air gap between the first
lens element and the second lens element along the optical axis,
G.sub.12, to satisfy the relation:
11.5 .ltoreq. G aa G 12 . ##EQU00002##
[0013] Another exemplary embodiment comprises controlling the air
gap between the fourth lens element and the fifth lens element
along the optical axis, G.sub.45, and G.sub.12 to satisfy the
relation:
G 45 G 12 .ltoreq. 5.5 . ##EQU00003##
[0014] Yet, another exemplary embodiment comprises controlling the
focal length of the third lens element, f.sub.3, and the effective
focal length of the optical imaging lens, f, to satisfy the
relation:
0 < f 3 f . ##EQU00004##
[0015] Yet, another exemplary embodiment comprises controlling
G.sub.aa and T.sub.1 to satisfy the relation:
G aa T 1 .ltoreq. 2.0 . ##EQU00005##
[0016] Still another exemplary embodiment comprises controlling
T.sub.1 and G.sub.12 to satisfy the relation:
6 .ltoreq. T 1 G 12 , or ##EQU00006## 9.5 .ltoreq. T 1 G 12 .
##EQU00006.2##
[0017] Still another exemplary embodiment comprises controlling
G.sub.aa to satisfy the relation:
G.sub.aa.ltoreq.1.3 mm.
[0018] Still another exemplary embodiment comprises controlling
G.sub.aa, ALT and G.sub.12 to satisfy the relation:
5 mm - 1 .ltoreq. G aa ALT .times. G 12 , 8 mm - 1 .ltoreq. G aa
ALT .times. G 12 , or ##EQU00007## 6.5 mm - 1 .ltoreq. G aa ALT
.times. G 12 . ##EQU00007.2##
[0019] Still another exemplary embodiment comprises controlling
G.sub.aa, G.sub.12 and G.sub.45 to satisfy the relation:
G aa G 12 + G 45 .ltoreq. 5.5 . ##EQU00008##
[0020] Aforesaid exemplary embodiments are not limited and could be
selectively incorporated in other embodiments described herein.
[0021] In exemplary embodiments, an aperture stop is provided for
adjusting the input of light of the system. For example, the
aperture stop is selectively provided but not limited to be
positioned at the object side of the first lens element.
[0022] In some exemplary embodiments, more details about the convex
or concave surface structure and/or the refractive power could be
incorporated for one specific lens element or broadly for plural
lens elements to enhance the control for the system performance
and/or resolution.
[0023] In another exemplary embodiment, a mobile device comprises a
housing and an image module positioned in the housing. The image
module comprises any of aforesaid exemplary embodiments of optical
imaging lens, a lens barrel, a module housing unit, and an image
sensor. The lens barrel is configured to provide a space where the
optical imaging lens having five lens elements is positioned. The
module housing unit is configured to provide a space where the lens
barrel is positioned. The image sensor is positioned at the
image-side of the optical imaging lens.
[0024] In exemplary embodiments, the module housing unit comprises,
but is not limited to, an lens backseat, which comprises a first
lens seat and a second lens seat, in which the first lens seat is
positioned close to the outside of the lens barrel and is assembled
along an axis, and the second lens seat is assembled along the axis
and surrounding the outside of the first lens seat. The first lens
seat could drive the lens barrel and the optical imaging lens
having five lens elements therein to move along the axis.
[0025] In exemplary embodiments, the module housing unit further
comprises, but is not limited to, an image sensor backseat
positioned between the first lens seat, the second lens seat and
the image sensor, and close to the second lens seat.
[0026] Through controlling the arrangement of the convex or concave
shape of the surface of the lens element(s) and/or refractive
power, the mobile device and the optical imaging lens thereof in
aforesaid exemplary embodiments achieve good optical
characteristics and effectively shorten the length of the optical
imaging lens.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] Exemplary embodiments will be more readily understood from
the following detailed description when read in conjunction with
the appended drawing, in which:
[0028] FIG. 1 is a cross-sectional view of a first embodiment of an
optical imaging lens having five lens elements according to the
present invention;
[0029] FIG. 2 is a chart of longitudinal spherical aberration and
other kinds of optical aberrations of the first embodiment of the
optical imaging lens according to the present disclosure;
[0030] FIG. 3 is a cross-sectional view of a lens element of the
optical imaging lens of an example embodiment of the present
invention;
[0031] FIG. 4 is a table of optical data for each lens element of
the first embodiment of an optical imaging lens according to the
present invention;
[0032] FIG. 5 is a table of aspherical data of the first embodiment
of the optical imaging lens according to the present invention;
[0033] FIG. 6 is a cross-sectional view of a second embodiment of
an optical imaging lens having five lens elements according to the
present invention;
[0034] FIG. 7 is a chart of longitudinal spherical aberration and
other kinds of optical aberrations of the second embodiment of the
optical imaging lens according to the present invention;
[0035] FIG. 8 is a table of optical data for each lens element of
the optical imaging lens of the second embodiment of the present
invention;
[0036] FIG. 9 is a table of aspherical data of the second
embodiment of the optical imaging lens according to the present
invention;
[0037] FIG. 10 is a cross-sectional view of a third embodiment of
an optical imaging lens having five lens elements according to the
present invention;
[0038] FIG. 11 is a chart of longitudinal spherical aberration and
other kinds of optical aberrations of the third embodiment of the
optical imaging lens according the present invention;
[0039] FIG. 12 is a table of optical data for each lens element of
the optical imaging lens of the third embodiment of the present
invention;
[0040] FIG. 13 is a table of aspherical data of the third
embodiment of the optical imaging lens according to the present
invention;
[0041] FIG. 14 is a cross-sectional view of a fourth embodiment of
an optical imaging lens having five lens elements according to the
present invention;
[0042] FIG. 15 is a chart of longitudinal spherical aberration and
other kinds of optical aberrations of the fourth embodiment of the
optical imaging lens according the present invention;
[0043] FIG. 16 is a table of optical data for each lens element of
the optical imaging lens of the fourth embodiment of the present
invention;
[0044] FIG. 17 is a table of aspherical data of the fourth
embodiment of the optical imaging lens according to the present
invention;
[0045] FIG. 18 is a cross-sectional view of a fifth embodiment of
an optical imaging lens having five lens elements according to the
present invention;
[0046] FIG. 19 is a chart of longitudinal spherical aberration and
other kinds of optical aberrations of the fifth embodiment of the
optical imaging lens according the present invention;
[0047] FIG. 20 is a table of optical data for each lens element of
the optical imaging lens of the fifth embodiment of the present
invention;
[0048] FIG. 21 is a table of aspherical data of a fifth embodiment
of the optical imaging lens according to the present invention;
[0049] FIG. 22 is a cross-sectional view of a sixth embodiment of
an optical imaging lens having five lens elements according to the
present invention;
[0050] FIG. 23 is a chart of longitudinal spherical aberration and
other kinds of optical aberrations of the sixth embodiment of the
optical imaging lens according the present invention;
[0051] FIG. 24 is a table of optical data for each lens element of
the optical imaging lens of the sixth embodiment of the present
invention;
[0052] FIG. 25 is a table of aspherical data of the sixth
embodiment of the optical imaging lens according to the present
invention;
[0053] FIG. 26 is a table for the values of
ALT T 1 , G aa G 12 , G 45 G 12 , f 3 f , G aa T 1 , T 1 G 12 , G
aa , G aa ALT .times. G 12 , G aa G 12 + G 45 ##EQU00009##
of all six example embodiments;
[0054] FIG. 27 is a structure of an example embodiment of a mobile
device; and
[0055] FIG. 28 is a partially enlarged view of the structure of
another example embodiment of a mobile device.
DETAILED DESCRIPTION OF THE INVENTION
[0056] For a more complete understanding of the present disclosure
and its advantages, reference is now made to the following
description taken in conjunction with the accompanying drawings, in
which like reference numbers indicate like features. Persons having
ordinary skill in the art will understand other varieties for
implementing example embodiments, including those described herein.
The drawings are not limited to specific scale and similar
reference numbers are used for representing similar elements. As
used in the disclosure and the appended claims, the terms "example
embodiment," "exemplary embodiment," and "present embodiment" do
not necessarily refer to a single embodiment, although it may, and
various example embodiments may be readily combined and
interchanged, without departing from the scope or spirit of the
present invention. Furthermore, the terminology as used herein is
for the purpose of describing example embodiments only and is not
intended to be a limitation of the invention. In this respect, as
used herein, the term "in" may include "in" and "on", and the terms
"a", "an" and "the" may include singular and plural references.
Furthermore, as used herein, the term "by" may also mean "from",
depending on the context. Furthermore, as used herein, the term
"if" may also mean "when" or "upon", depending on the context.
Furthermore, as used herein, the words "and/or" may refer to and
encompass any and all possible combinations of one or more of the
associated listed items.
[0057] Example embodiments of an optical imaging lens may comprise
a first lens element, a second lens element, a third lens element,
a fourth lens element, and a fifth lens element, each of the lens
elements has an object-side surface facing toward the object side
and an image-side surface facing toward the image side. These lens
elements may be arranged sequentially from an object side to an
image side, and example embodiments of the optical imaging lens as
a whole may comprise the five lens elements having refractive
power. By controlling the convex or concave shape and/or the
refractive power characteristics of the surfaces of the lens
elements, etc., the length of the optical imaging lens may be
shortened while providing good optical performance. In an example
embodiment: the first lens element has positive refractive power,
and the object-side surface thereof comprises a convex portion in a
vicinity of an optical axis; the second lens element has negative
refractive power, the object-side surface thereof comprises a
convex portion in a vicinity of the optical axis, and the
image-side surface thereof comprises a concave portion in a
vicinity of the optical axis; the image-side surface of the third
lens element comprises a convex portion in a vicinity of a
periphery of the third lens element; the image-side surface of the
fourth lens element comprises a convex portion in a vicinity of the
optical axis; and the object-side surface of the fifth lens element
comprises a convex portion in a vicinity of the optical axis, and
the image-side surface of the fifth lens element comprises a
concave portion in a vicinity of the optical axis and a convex
portion in a vicinity of a periphery of the fifth lens element.
[0058] Each lens element with aforesaid design is considered about
the optical characteristics and the lengths of the optical imaging
lens. The first lens element having positive refractive power and
an object-side surface comprising a convex portion in a vicinity of
the optical axis has better light converge ability, and together
with an aperture stop provided at the object side of the first lens
element could effectively shorten the lengths of the optical
imaging lens. The second lens element having negative refractive
power and an object-side surface comprising a convex portion in a
vicinity of the optical axis and an image-side surface thereof
comprising a concave portion in a vicinity of the optical axis, and
together with the third lens element comprising an image-side
surface comprising a convex portion in a vicinity of a periphery of
the third lens element could eliminate the aberration of the
optical imaging lens. The fourth lens element comprising an
image-side surface comprising a convex portion in a vicinity of the
optical axis has better light converge ability. The fifth lens
element comprising an object-side surface comprising a convex
portion in a vicinity of the optical axis, and an image-side
surface comprising a concave portion in a vicinity of the optical
axis and a convex portion in a vicinity of a periphery of the fifth
lens element could correct the field curvature of the optical
imaging lens, reduce the high order aberration of the optical
imaging lens, and depresses the angle of the chief ray (the
incident angle of the light onto the image sensor), and then the
sensitivity of the whole system is promoted to achieve good optical
characteristics.
[0059] In another exemplary embodiment, a total thickness of all
five lens elements, ALT, and a central thickness of the first lens
element along the optical axis, T.sub.1, satisfy the following
equation:
ALT T 1 .ltoreq. 4. Equation ( 1 ) ##EQU00010##
[0060] Reference is now made to equation (1). A person having
ordinary skill in the art would readily understand that the
shortened ratio of ALT is larger than the shortened ratio of
T.sub.1. Since the first lens element has positive refractive
power, the thickness of the first lens element should not be too
thin. Otherwise, the light convergence effect of the optical
imaging lens is insufficient. On the other hand, when the total
thickness of all five lens elements ALT is shortened, it could also
reduce the thickness of the lens elements besides the first lens
element for more shortened length ratio. Therefore, the light
convergence effect and the total length of the optical imaging lens
have proper correlation if satisfying equation (1). Considering a
reasonable optical imaging lens length, equation (1) may be further
restricted by a lower limit, for example but not limited to, as
follows:
3 .ltoreq. ALT T 1 .ltoreq. 4. Equation ( 1 ' ) ##EQU00011##
[0061] In another exemplary embodiment, the relations of the sum of
all air gaps between the lens elements along the optical axis and
each air gap between two adjacent lens element along the optical
axis could be controlled, and an example among them is controlling
the sum of all air gaps from the first lens element to the fifth
lens element along the optical axis, G.sub.aa, and an air gap
between the first lens element and the second lens element along
the optical axis, G.sub.12, to satisfy the following equation:
11.5 .ltoreq. G aa G 12 . Equation ( 2 ) ##EQU00012##
[0062] Reference is now made to equation (2). A person having
ordinary skill in the art would readily understand that the
shortened ratio of G.sub.aa is smaller than the shortened ratio of
G.sub.12. Since the object-side surface of the second lens element
comprises a convex portion in a vicinity of the optical axis, the
distance from the first lens element to the second lens element
could be more shortened, such that it could effectively shorten the
length of the optical imaging lens. Considering a reasonable
optical imaging lens length, equation (2) may be further restricted
by a upper limit, for example but not limited to, as follows:
11.5 .ltoreq. G aa G 12 .ltoreq. 25. Equation ( 2 ' )
##EQU00013##
[0063] In another exemplary embodiment, the air gap between the
fourth lens element and the fifth lens element along the optical
axis, G.sub.45, and G.sub.12 satisfy the following equation:
G 45 G 12 .ltoreq. 5.5 . Equation ( 3 ) ##EQU00014##
[0064] Reference is now made to equation (3). A person having
ordinary skill in the art would readily understand that the
shortened optical imaging lens length of G.sub.45 is larger than
the shortened range of G.sub.12. Since the image-side surface of
the fourth lens element comprises a convex portion in a vicinity of
the optical axis and the object-side surface of the fifth lens
element comprises a convex portion in a vicinity of the optical
axis, the shortened range of G.sub.45 is larger than the shortened
range of G.sub.12, which is proper arrangement for shortening the
length of the optical imaging lens. Considering a reasonable
optical imaging lens length, equation (3) may be further restricted
by a upper limit, for example but not limited to, as follows:
0.8 .ltoreq. G 45 G 12 .ltoreq. 5.5 . Equation ( 3 ' )
##EQU00015##
[0065] As all mentioned above, the shortened ratios of G.sub.12 and
G.sub.45 are larger than the shortened ratios of other air gaps
during the process of shortening the length of the optical imaging
lens.
[0066] In another exemplary embodiment, the focal length of the
third lens element, f.sub.3, and the effective focal length of the
optical imaging lens, f, satisfy the following equation:
0 < f 3 f . Equation ( 4 ) ##EQU00016##
[0067] Reference is now made to equation (4). A person having
ordinary skill in the art would readily understand that the third
lens element, the first lens element, and the second lens element
are constructed in positive, negative, and positive structure
symmetrically, which has better aberration elimination ability.
[0068] In another exemplary embodiment, G.sub.aa and T.sub.1
satisfy the following equation:
G aa T 1 .ltoreq. 2.0 . Equation ( 5 ) ##EQU00017##
[0069] Reference is now made to equation (5). A person having
ordinary skill in the art would readily understand when T.sub.1
becomes longer, it indicates the light converge ability of the
first lens element is better. Accordingly, when the light emitted
from the first lens element incident to the second lens element at
the same height, G.sub.12 is shortened as well as G.sub.aa is
shortened, which is favorable for shortening the length of the
optical imaging lens. Considering a reasonable optical imaging lens
length, equation (3) may be further restricted by a upper limit,
for example but not limited to, as follows:
1 .ltoreq. G aa T 1 .ltoreq. 2.0 . Equation ( 5 ' )
##EQU00018##
[0070] Preferably, G.sub.aa and T.sub.1 may further satisfy the
following equation:
1.3 .ltoreq. G aa T 1 .ltoreq. 2.0 Equation ( 5 '' )
##EQU00019##
[0071] In another exemplary embodiment, T.sub.1 and G.sub.12
satisfy the following equation:
6 .ltoreq. T 1 G 12 Equation ( 6 ) ##EQU00020##
[0072] Reference is now made to equation (6). A person having
ordinary skill in the art would readily understand when considering
the light converge ability of the first lens element and the height
of the incident light to the second lens element, the arrangement
of T.sub.1 and G.sub.12 in the proper range could reduce the length
of the optical imaging lens and maintain good optical
characteristics.
[0073] Preferably, T.sub.1 and G.sub.12 may further satisfy the
following equation:
9.5 .ltoreq. T 1 G 12 Equation ( 6 ' ) ##EQU00021##
[0074] Considering a reasonable optical imaging lens length,
equation (6) may be further restricted by an upper limit, for
example but not limited to, as follows:
6 .ltoreq. T 1 G 12 .ltoreq. 17. Equation ( 6 '' ) ##EQU00022##
[0075] In another exemplary embodiment, G.sub.aa satisfies the
following equation:
G.sub.aa.ltoreq.1.3 mm Equation (7).
[0076] Reference is now made to equation (7). A person having
ordinary skill in the art would readily understand G.sub.aa should
not be excessive, otherwise the length of the optical imaging lens
could not be shortened. However, if G.sub.aa is too small, the
production difficulty is quite high. Accordingly, G.sub.aa may be
preferably further restricted by a lower limit, for example but not
limited to, as follows:
0.65 mm.ltoreq.G.sub.aa.ltoreq.1.3 mm Equation (7').
[0077] In another exemplary embodiment, G.sub.aa, ALT, and G.sub.12
satisfy the following equation:
5 mm - 1 .ltoreq. G aa ALT .times. G 12 . Equation ( 8 )
##EQU00023##
[0078] Reference is now made to equation (8). A person having
ordinary skill in the art would readily understand G.sub.aa, ALT,
and G.sub.12 are determined in the proper range based on the
preferable length of the optical imaging lens, otherwise, it is
unfavorable for reducing the length of the optical imaging lens if
ALT, and G.sub.12 are excessive.
[0079] G.sub.aa, ALT, and G.sub.12 may preferably satisfy the
following equations:
6.5 mm - 1 .ltoreq. G aa ALT .times. G 12 ; or Equation ( 8 ' ) 8
mm - 1 .ltoreq. G aa ALT .times. G 12 . Equation ( 8 '' )
##EQU00024##
[0080] Furthermore, Equation (8) may be preferably further
restricted by an upper limit, for example but not limited to, as
follows:
5 mm - 1 .ltoreq. G aa ALT .times. G 12 .ltoreq. 13.5 mm - 1 .
Equation ( 8 ''' ) ##EQU00025##
[0081] In another exemplary embodiment, G.sub.aa, G.sub.12, and
G.sub.45 satisfy the following equation:
G aa G 12 + G 45 .ltoreq. 5.5 Equation ( 9 ) ##EQU00026##
[0082] Reference is now made to equation (9). A person having
ordinary skill in the art would readily understand G.sub.12 and
G.sub.45 are two smaller air gap in the arrangement of the optical
imaging lens, however, if G.sub.12 and G.sub.45 are too small, the
production difficulty is quite high. Therefore, G.sub.aa, G.sub.12,
and G.sub.45 have proper correlation if satisfying equation
(9).
[0083] Equation (9) may be preferably further restricted by a lower
limit, for example but not limited to, as follows:
2 .ltoreq. G aa G 12 + G 45 .ltoreq. 5.5 Equation ( 9 ' )
##EQU00027##
[0084] When implementing example embodiments, more details about
the convex or concave surface structure and/or the refractive power
may be incorporated for one specific lens element or broadly for
plural lens elements to enhance the control for the system
performance and/or resolution, as illustrated in the following
embodiments. It is noted that the details listed here could be
incorporated in example embodiments if no inconsistency occurs.
[0085] Several exemplary embodiments and associated optical data
will now be provided for illustrating example embodiments of
optical imaging lens with good optical characteristics and a
shortened length. Reference is now made to FIGS. 1-5. FIG. 1
illustrates an example cross-sectional view of an optical imaging
lens 1 having five lens elements of the optical imaging lens
according to a first example embodiment. FIG. 2 shows example
charts of longitudinal spherical aberration and other kinds of
optical aberrations of the optical imaging lens 1 according to an
example embodiment. FIG. 3 depicts another example cross-sectional
view of a lens element of the optical imaging lens 1 according to
an example embodiment. FIG. 4 illustrates an example table of
optical data of each lens element of the optical imaging lens 1
according to an example embodiment. FIG. 5 depicts an example table
of aspherical data of the optical imaging lens 1 according to an
example embodiment.
[0086] As shown in FIG. 1, the optical imaging lens 1 of the
present embodiment comprises, in order from an object side A1 to an
image side A2, an aperture stop 100, a first lens element 110, a
second lens element 120, a third lens element 130, and a fourth
lens element 140, and a fifth lens 150. A filtering unit 160 and an
image plane 170 of an image sensor are positioned at the image side
A2 of the optical image lens 1. More specifically, the filtering
unit 160 is positioned between the fifth lens 150 and the image
plane 170 of the image sensor. The filtering unit 160, having an
object-side surface 161 and an image-side surface 162, filters
light with specific wavelength from the light passing optical
imaging lens 1. For example, IR light is filtered or selectively
absorbed by the filtering unit 160, and this will prohibit the IR
light which is not seen by human eyes from producing an image on
the image plane 170 of the image sensor.
[0087] Exemplary embodiments of each lens element of the optical
imaging lens 1 will now be described with reference to the
drawings. Detail about the structure of each lens element of the
optical imaging lens 1 is provided below.
[0088] Each of the first, second, third, fourth, and fifth lens
elements 110, 120, 130, 140, 150 has a respective object-side
surface 111, 121, 131, 141, 151 facing toward the object side A1
and a respective image-side surface 112, 122, 132, 142, 152 facing
toward the image side A2. The aperture stop 100 is positioned in
front of the first lens element 110. The first lens element 110 has
positive refractive power and may be made of plastic material. The
object-side surface 111 is a convex surface, which comprises a
convex portion 1111 in a vicinity of the optical axis. The
image-side surface 112 comprises a concave portion 1121 in a
vicinity of the optical axis, and a convex portion 1122 in a
vicinity of a periphery of the first lens element 110. The
object-side surface 111 and the image-side surface 112 may be both
aspherical surfaces.
[0089] The second lens element 120 has negative refractive power
and may be made of plastic material. The object-side surface 121 is
a convex surface, which comprises a convex portion 1211 in a
vicinity of the optical axis. The image-side surface 122 is a
concave surface, which comprises a concave portion 1221 in a
vicinity of the optical axis. The object-side surface 121 and the
image-side surface 122 may be both aspherical surfaces.
[0090] The third lens element 130 may have positive refractive
power and may be made of plastic material. The object-side surface
131 comprises a convex portion 1311 in a vicinity of the optical
axis and a concave portion 1312 in a vicinity of a periphery of the
third lens element 130. The image-side surface 132 comprises a
concave portion 1321 in a vicinity of the optical axis, and a
convex portion 1322 in a vicinity of a periphery of the third lens
element 130. The object-side surface 131 and the image-side surface
132 may be both aspherical surfaces.
[0091] The fourth lens element 140 may have positive refractive
power and may be made of plastic material. The object-side surface
141 is a concave surface. The image-side surface 142 is a convex
surface, which comprises a convex portion 1421 in a vicinity of the
optical axis. The object-side surface 141 and the image-side
surface 142 may be both aspherical surfaces.
[0092] The fifth lens element 150 may have negative refractive
power and may be made of plastic material. The object-side surface
151 comprises a convex portion 1511 in a vicinity of the optical
axis. The image-side surface 152 comprises a concave portion 1521
in a vicinity of the optical axis, and a convex portion 1522 in a
vicinity of a periphery of the fifth lens element 150. The
object-side surface 151 and the image-side surface 152 may be both
aspherical surfaces.
[0093] In example embodiments, air gaps exist between the lens
elements 110-150, the filtering unit 160, and the image plane 170
of the image sensor. For example, FIG. 1 illustrates the air gaps
d1 existing between the first lens element 110 and the second lens
element 120, the air gap d2 existing between the second lens
element 120 and the third lens element 130, the air gap d3 existing
between the third lens element 130 and the fourth lens element 140,
the air gap d4 existing between the fourth lens element 140 and the
fifth lens element 150, the air gap d5 existing between the fifth
lens element 150 and the filtering unit 160, and the air gap d6
existing between the filtering unit 160 and the image plane 170 of
the image sensor. However, in other embodiments, any of the
aforesaid air gaps may or may not exist. For example, the profiles
of opposite surfaces of any two adjacent lens elements may
correspond to each other, and in such situation, the air gaps may
not exist. The air gap d1 is denoted by G.sub.12, the air gap d3 is
denoted by G.sub.34, and the sum of all air gaps d1, d2, d3, d4
between the first though fifth lens elements is denoted by
G.sub.aa.
[0094] FIG. 4 depicts the optical characteristics of each lens
elements in the optical imaging lens 1 of the present invention,
wherein the values of
ALT T 1 , G aa G 12 , G 45 G 12 , f 3 f , G aa T 1 , T 1 G 12 , G
aa , G aa ALT .times. G 12 , G aa G 12 + G 45 ##EQU00028##
are:
ALT T 1 = 3.92 , ##EQU00029##
satisfying equations (1), and (1');
G aa G 12 = 16.78 , ##EQU00030##
satisfying equations (2), and (2');
G 45 G 12 = 5.42 , ##EQU00031##
satisfying equations (3), and (3');
f 3 f = 38.26 , ##EQU00032##
satisfying equations (4);
G aa T 1 = 1.76 , ##EQU00033##
satisfying equations (5), (5'), and (5'');
T 1 G 12 = 9.53 , ##EQU00034##
satisfying equations (6), (6'), and (6'');
[0095] G.sub.aa=0.86 mm, satisfying equations (7), and (7');
G aa ALT .times. G 12 = 8.74 mm - 1 , ##EQU00035##
satisfying equations (8), (8'), (8''), and (8'''); and
G aa G 12 + G 45 = 2.61 , ##EQU00036##
satisfying equations (9), and (9').
[0096] The distance from the object-side surface 111 of the first
lens element 110 to the image plane 170 is 3.68 mm, and the length
of the optical imaging lens 1 is indeed shortened.
[0097] Please note that, in example embodiments, to clearly
illustrate the structure of each lens element, only the part where
light passes, is shown. For example, taking the first lens element
110 as an example, FIG. 1 illustrates the object-side surface 111
and the image-side surface 112. However, when implementing each
lens element of the present embodiment, a fixing part for
positioning the lens elements inside the optical imaging lens 1 may
be formed selectively. Based on the first lens element 110, please
refer to FIG. 3, which illustrates the first lens element 110
further comprising a fixing part. Here the fixing part is not
limited to a protruding part 113 extending from the object-side
surface 111 and the image-side surface 112 to the edge of the first
lens element 110 for mounting the first lens element 110 in the
optical imaging lens 1, and ideally, light for imaging will not
pass through the protruding part 113.
[0098] Please note that, in example embodiments, to clearly
illustrate the structure of each lens element, only the part where
light passes, is shown. For example, taking the first lens element
110 as an example, FIG. 1 illustrates the object-side surface 111
and the image-side surface 112. However, when implementing each
lens element of the present embodiment, a fixing part for
positioning the lens elements inside the optical imaging lens 1 may
be formed selectively. Based on the first lens element 110, please
refer to FIG. 3, which illustrates the first lens element 110
further comprising a fixing part. Here the fixing part is not
limited to a protruding part 113 extending from the object-side
surface 111 and the image-side surface 112 to the edge of the first
lens element 110 for mounting the first lens element 110 in the
optical imaging lens 1, and ideally, light for imaging will not
pass through the protruding part 113.
[0099] The aspherical surfaces, including the object-side surfaces
111, 121, 131, 141, 151 and the image-side surfaces 112, 122, 132,
142, 152 are all defined by the following aspherical formula:
Z ( Y ) = Y 2 R / ( 1 + 1 - ( 1 + K ) Y 2 R 2 ) + i = 1 n a 2 i
.times. Y 2 i ##EQU00037##
[0100] wherein,
[0101] R represents the radius of the surface of the lens
element;
[0102] Z represents the depth of the aspherical surface (the
perpendicular distance between the point of the aspherical surface
at a distance Y from the optical axis and the tangent plane of the
vertex on the optical axis of the aspherical surface);
[0103] Y represents the perpendicular distance between the point of
the aspherical surface and the optical axis;
[0104] K represents a conic constant; and
[0105] a.sub.2i represents a aspherical coefficient of 2i.sup.th
order.
[0106] The values of each aspherical parameter, K, and
a.sub.4.about.a.sub.12 of each lens element 110, 120, 130, 140, 150
are represented in FIG. 5.
[0107] As illustrated in FIG. 2, the optical imaging lens 1 of the
present example embodiment shows great characteristics in the
longitudinal spherical aberration (a), astigmatism aberration in
the sagittal direction (b), astigmatism aberration in the
tangential direction (c), and distortion aberration (d). Therefore,
according to above illustration, the optical imaging lens 1 of the
example embodiment indeed achieves great optical performance and
the length of the optical imaging lens 1 is effectively
shortened.
[0108] Reference is now made to FIGS. 6-9. FIG. 6 illustrates an
example cross-sectional view of an optical imaging lens 2 having
five lens elements of the optical imaging lens according to a
second example embodiment. FIG. 7 shows example charts of
longitudinal spherical aberration and other kinds of optical
aberrations of the optical imaging lens 2 according to an example
embodiment. FIG. 8 shows an example table of optical data of each
lens element of the optical imaging lens 2 according to the second
example embodiment. FIG. 9 shows an example table of aspherical
data of the optical imaging lens 2 according to the second example
embodiment.
[0109] As shown in FIG. 6, the second embodiment is similar to the
first embodiment. The optical imaging lens 2, in an order from an
object side A1 to an image side A2, comprises an aperture stop 200,
first lens element to fifth lens element 210-250. A filtering unit
260 and an image plane 270 of an image sensor are positioned at the
image side A2 of the optical imaging lens 2. The arrangement of the
convex or concave surface structures, including the object-side
surfaces 211-251 and image-side surfaces 212-252, and the
refractive power of the lens elements 210-250 is same with the
optical imaging lens 1. The difference between the optical imaging
lens 1 and the optical imaging lens 2 is the image-side surface 212
of the optical imaging lens 2 is a convex surface. Additionally,
the values of the central thicknesses of the lens elements 210-250
and the air gaps between the lens elements 210-250 are slight
different from the values of the optical imaging lens 1.
[0110] Please refer to FIG. 8 for the optical characteristics of
each lens elements in the optical imaging lens 2 of the present
embodiment, wherein the values of
ALT T 1 , G aa G 12 , G 45 G 12 , f 3 f , G aa T 1 , T 1 G 12 , G
aa , G aa ALT .times. G 12 , G aa G 12 + G 45 ##EQU00038##
are:
ALT T 1 = 3.50 , ##EQU00039##
satisfying equations (1), and (1');
G aa G 12 = 23.00 , ##EQU00040##
satisfying equations (2), and (2');
G 45 G 12 = 5.50 , ##EQU00041##
satisfying equations (3), and (3');
f 3 f = 19.80 , ##EQU00042##
satisfying equations (4);
G aa T 1 = 1.52 , ##EQU00043##
satisfying equations (5), (5'), and (5'');
T 1 G 12 = 15.10 , ##EQU00044##
satisfying equations (6), (6'), and (6'');
[0111] G.sub.aa=0.83 mm, satisfying equations (7), and (7');
G aa ALT .times. G 12 = 12.09 mm - 1 , ##EQU00045##
salistymg equations (8), (8'), (8''), and (8'''); and
G aa G 12 + G 45 = 3.54 , ##EQU00046##
satisfying equations (9), and (9').
[0112] The distance from the object-side surface 211 of the first
lens element 210 to the image plane 270 is 3.69 mm, and the length
of the optical imaging lens 2 is indeed shortened.
[0113] As shown in FIG. 7, the optical imaging lens 2 of the
present embodiment shows great characteristics in longitudinal
spherical aberration (a), astigmatism in the sagittal direction
(b), astigmatism in the tangential direction (c), and distortion
aberration (d). Therefore, according to the above illustration, the
optical imaging lens of the present embodiment indeed shows great
optical performance and the length of the optical imaging lens 2 is
effectively shortened.
[0114] Reference is now made to FIGS. 10-13. FIG. 10 illustrates an
example cross-sectional view of an optical imaging lens 3 having
five lens elements of the optical imaging lens according to a third
example embodiment. FIG. 11 shows example charts of longitudinal
spherical aberration and other kinds of optical aberrations of the
optical imaging lens 3 according to an example embodiment. FIG. 12
shows an example table of optical data of each lens element of the
optical imaging lens 3 according to the third example embodiment.
FIG. 13 shows an example table of aspherical data of the optical
imaging lens 3 according to the third example embodiment.
[0115] As shown in FIG. 10, the third embodiment is similar to the
first embodiment. The optical imaging lens 3, in an order from an
object side A1 to an image side A2, comprises an aperture stop 300,
first lens element to fifth lens element 310-350. A filtering unit
360 and an image plane 370 of an image sensor are positioned at the
image side A2 of the optical imaging lens 3. The arrangement of the
convex or concave surface structures, including the object-side
surfaces 311-351 and image-side surfaces 312-352, and the
refractive power of the lens elements 310-350 is same with the
optical imaging lens 1. The difference between the optical imaging
lens 1 and the optical imaging lens 3 is the image-side surface 312
of the optical imaging lens 3 is a convex surface. Additionally,
the values of the central thicknesses of the lens elements 310-350
and the air gaps between the lens elements 310-350 are slight
different from the values of the optical imaging lens 1.
[0116] Please refer to FIG. 12 for the optical characteristics of
each lens elements in the optical imaging lens 2 of the present
embodiment, wherein the values of
ALT T 1 , G aa G 12 , G 45 G 12 , f 3 f , G aa T 1 , T 1 G 12 , G
aa , G aa ALT .times. G 12 , G aa G 12 + G 45 ##EQU00047##
are:
ALT T 1 = 3.10 , ##EQU00048##
satisfying equations (1), and (1');
G aa G 12 = 18.94 , ##EQU00049##
[0117] satisfying equations (2), and (2');
G 45 G 12 = 5.24 , ##EQU00050##
satisfying equations (3), and (3');
f 3 f = 8.66 , ##EQU00051##
satisfying equations (4);
G aa T 1 = 1.41 , ##EQU00052##
satisfying equations (5), (5'), and (5'');
T 1 G 12 = 13.46 , ##EQU00053##
satisfying equations (6), (6'), and (6'');
[0118] G.sub.aa=0.87 mm, satisfying equations (7), and (7');
G aa ALT .times. G 12 = 9.87 mm - 1 , ##EQU00054##
satisfying equations (8), (8'), (8''), and (8'''); and
G aa G 12 + G 45 = 3.04 , ##EQU00055##
satisfying equations (9), and (9').
[0119] The distance from the object-side surface 311 of the first
lens element 310 to the image plane 370 is 3.69 mm, and the length
of the optical imaging lens 3 is indeed shortened.
[0120] As shown in FIG. 11, the optical imaging lens 3 of the
present embodiment shows great characteristics in longitudinal
spherical aberration (a), astigmatism in the sagittal direction
(b), astigmatism in the tangential direction (c), and distortion
aberration (d). Therefore, according to the above illustration, the
optical imaging lens of the present embodiment indeed shows great
optical performance and the length of the optical imaging lens 3 is
effectively shortened.
[0121] Reference is now made to FIGS. 14-17. FIG. 14 illustrates an
example cross-sectional view of an optical imaging lens 4 having
five lens elements of the optical imaging lens according to a
fourth example embodiment. FIG. 15 shows example charts of
longitudinal spherical aberration and other kinds of optical
aberrations of the optical imaging lens 4 according to an example
embodiment. FIG. 16 shows an example table of optical data of each
lens element of the optical imaging lens 4 according to the fourth
example embodiment. FIG. 17 shows an example table of aspherical
data of the optical imaging lens 2 according to the fourth example
embodiment.
[0122] As shown in FIG. 14, the fourth embodiment is similar to the
first embodiment. The optical imaging lens 2, in an order from an
object side A1 to an image side A2, comprises an aperture stop 400,
first lens element to fifth lens element 410-450. A filtering unit
460 and an image plane 470 of an image sensor are positioned at the
image side A2 of the optical imaging lens 4. The arrangement of the
convex or concave surface structures, including the object-side
surfaces 411-451 and image-side surfaces 412-452, and the
refractive power of the lens elements 410-450 is same with the
optical imaging lens 1. The difference between the optical imaging
lens 1 and the optical imaging lens 4 the values of the central
thicknesses of the lens elements 410-450 and the air gaps between
the lens elements 410-450 are slight different from the values of
the optical imaging lens 1.
[0123] Please refer to FIG. 16 for the optical characteristics of
each lens elements in the optical imaging lens 4 of the present
embodiment, wherein the values of
ALT T 1 , G aa G 12 , G 45 G 12 , f 3 f , G aa T 1 , T 1 G 12 , G
aa , G aa ALT .times. G 12 , G aa G 12 + G 45 ##EQU00056##
are:
ALT T 1 = 3.71 , ##EQU00057##
satisfying equations (1), and (1');
G aa G 12 = 14.02 , ##EQU00058##
satisfying equations (2), and (2');
G 45 G 12 = 4.45 , ##EQU00059##
satisfying equations (3), and (3');
f 3 f = 6.22 , ##EQU00060##
satisfying equations (4);
G aa T 1 = 1.82 , ##EQU00061##
satisfying equations (5), (5'), and (5'');
T 1 G 12 = 7.7 , ##EQU00062##
satisfying equations (6), and (6'');
[0124] G.sub.aa=0.91 mm, satisfying equations (7), and (7');
G aa ALT .times. G 12 = 7.55 mm - 1 , ##EQU00063##
satisfying equations (8), (8'), and (8'''); and
G aa G 12 + G 45 = 2.57 , ##EQU00064##
satisfying equations (9), and (9').
[0125] The distance from the object-side surface 411 of the first
lens element 410 to the image plane 470 is 3.63 mm, and the length
of the optical imaging lens 4 is indeed shortened.
[0126] As shown in FIG. 15, the optical imaging lens 4 of the
present embodiment shows great characteristics in longitudinal
spherical aberration (a), astigmatism in the sagittal direction
(b), astigmatism in the tangential direction (c), and distortion
aberration (d). Therefore, according to the above illustration, the
optical imaging lens of the present embodiment indeed shows great
optical performance and the length of the optical imaging lens 4 is
effectively shortened.
[0127] Reference is now made to FIGS. 18-21. FIG. 18 illustrates an
example cross-sectional view of an optical imaging lens 5 having
five lens elements of the optical imaging lens according to a fifth
example embodiment. FIG. 19 shows example charts of longitudinal
spherical aberration and other kinds of optical aberrations of the
optical imaging lens 5 according to an example embodiment. FIG. 20
shows an example table of optical data of each lens element of the
optical imaging lens 5 according to the fifth example embodiment.
FIG. 21 shows an example table of aspherical data of the optical
imaging lens 5 according to the fifth example embodiment.
[0128] As shown in FIG. 18, the fifth embodiment is similar to the
first embodiment. The optical imaging lens 5, in an order from an
object side A1 to an image side A2, comprises an aperture stop 500,
first lens element to fifth lens element 510-550. A filtering unit
560 and an image plane 570 of an image sensor are positioned at the
image side A2 of the optical imaging lens 5. The arrangement of the
convex or concave surface structures, including the object-side
surfaces 511-551 and image-side surfaces 512-552, and the
refractive power of the lens elements 510-550 is same with the
optical imaging lens 1. The difference between the optical imaging
lens 1 and the optical imaging lens 5 is the values of the central
thicknesses of the lens elements 510-550 and the air gaps between
the lens elements 510-550 are slight different from the values of
the optical imaging lens 1.
[0129] Please refer to FIG. 20 for the optical characteristics of
each lens elements in the optical imaging lens 5 of the present
embodiment, wherein the values of
ALT T 1 , G aa G 12 , G 45 G 12 , f 3 f , G aa T 1 , T 1 G 12 , G
aa , G aa ALT .times. G 12 , G aa G 12 + G 45 ##EQU00065##
are:
ALT T 1 = 3.69 , ##EQU00066##
satisfying equations (1), and (1');
G aa G 12 = 11.50 , ##EQU00067##
satisfying equations (2), and (2');
G 45 G 12 = 1.30 , ##EQU00068##
satisfying equations (3), and (3');
f 3 f = 6.22 , ##EQU00069##
satisfying equations (4);
G aa T 1 = 1.85 , ##EQU00070##
satisfying equations (5), (5'), and (5'');
T 1 G 12 = 6.21 , ##EQU00071##
satisfying equations (6), and (6'');
[0130] G.sub.aa=1.15 mm, satisfying equations (7), and (7');
G aa ALT .times. G 12 = 5.02 mm - 1 , ##EQU00072##
satisfying equations (8), and (8'''); and
G aa G 12 + G 45 = 5.00 , ##EQU00073##
satisfying equations (9), and (9').
[0131] The distance from the object-side surface 511 of the first
lens element 510 to the image plane 570 is 4.49 mm, and the length
of the optical imaging lens 5 is indeed shortened.
[0132] As shown in FIG. 19, the optical imaging lens 5 of the
present embodiment shows great characteristics in longitudinal
spherical aberration (a), astigmatism in the sagittal direction
(b), astigmatism in the tangential direction (c), and distortion
aberration (d). Therefore, according to the above illustration, the
optical imaging lens of the present embodiment indeed shows great
optical performance and the length of the optical imaging lens 5 is
effectively shortened.
[0133] Reference is now made to FIGS. 22-25. FIG. 22 illustrates an
example cross-sectional view of an optical imaging lens 6 having
five lens elements of the optical imaging lens according to a sixth
example embodiment. FIG. 23 shows example charts of longitudinal
spherical aberration and other kinds of optical aberrations of the
optical imaging lens 6 according to an example embodiment. FIG. 24
shows an example table of optical data of each lens element of the
optical imaging lens 6 according to the sixth example embodiment.
FIG. 25 shows an example table of aspherical data of the optical
imaging lens 6 according to the sixth example embodiment.
[0134] As shown in FIG. 22, the sixth embodiment is similar to the
first embodiment. The optical imaging lens 6, in an order from an
object side A1 to an image side A2, comprises an aperture stop 600,
first lens element to fifth lens element 610-650. A filtering unit
660 and an image plane 670 of an image sensor are positioned at the
image side A2 of the optical imaging lens 6. The arrangement of the
convex or concave surface structures, including the object-side
surfaces 611-651 and image-side surfaces 612-652, and the
refractive power of the lens elements 610-650 is same with the
optical imaging lens 1. The difference between the optical imaging
lens 1 and the optical imaging lens 6 is the values of the central
thicknesses of the lens elements 610-650 and the air gaps between
the lens elements 610-650 are slight different from the values of
the optical imaging lens 1.
[0135] Please refer to FIG. 24 for the optical characteristics of
each lens elements in the optical imaging lens 6 of the present
embodiment, wherein the values of
ALT T 1 , G aa G 12 , G 45 G 12 , f 3 f , G aa T 1 , T 1 G 12 , G
aa , G aa ALT .times. G 12 , G aa G 12 + G 45 ##EQU00074##
are:
ALT T 1 = 3.95 , ##EQU00075##
satisfying equations (1), and (1');
G aa G 12 = 11.83 , ##EQU00076##
satisfying equations (2), and (2');
G 45 G 12 = 3.31 , ##EQU00077##
satisfying equations (3), and (3');
f 3 f = 6.22 , ##EQU00078##
satisfying equations (4);
G aa T 1 = 1.95 , ##EQU00079##
satisfying equations (5), (5'), and (5'');
T 1 G 12 = 6.05 , ##EQU00080##
satisfying equations (6), and (6'');
[0136] G.sub.aa=0.90 mm, satisfying equations (7), and (7');
G aa ALT .times. G 12 = 6.50 mm - 1 , ##EQU00081##
satisfying equations (8), (8'), and (8'''); and
G aa G 12 + G 45 = 2.74 , ##EQU00082##
satisfying equations (9), and (9').
[0137] The distance from the object-side surface 611 of the first
lens element 610 to the image plane 670 is 3.65 mm, and the length
of the optical imaging lens 6 is indeed shortened.
[0138] As shown in FIG. 23, the optical imaging lens 6 of the
present embodiment shows great characteristics in longitudinal
spherical aberration (a), astigmatism in the sagittal direction
(b), astigmatism in the tangential direction (c), and distortion
aberration (d). Therefore, according to the above illustration, the
optical imaging lens of the present embodiment indeed shows great
optical performance and the length of the optical imaging lens 6 is
effectively shortened.
[0139] Above all, the optical imaging lenses 1, 2, and 3
satisfying
9.5 .ltoreq. T 1 G 12 ##EQU00083##
have better effect of astigmatism in the tangential direction than
the optical imaging lenses 4, 5, and 6 satisfying
6 .ltoreq. T 1 G 12 .ltoreq. 9.5 ##EQU00084##
have. Specifically, although the optical imaging lens
satisfying
6 .ltoreq. T 1 G 12 .ltoreq. 9.5 ##EQU00085##
could reduce the length of the optical imaging lens and maintain
good optical characteristics, the optical imaging lens
satisfying
9.5 .ltoreq. T 1 G 12 ##EQU00086##
has better effect of correcting astigmatism (mainly in the
tangential direction).
[0140] Additionally, the optical imaging lenses 1, 2, and 3
satisfying
8 mm - 1 .ltoreq. G aa ALT .times. G 12 ##EQU00087##
have better effect of astigmatism in the tangential direction than
the optical imaging lenses 4, 5, and 6 satisfying
5 mm - 1 .ltoreq. G aa ALT .times. G 12 .ltoreq. 8 mm - 1
##EQU00088##
have.
[0141] Please refer to FIG. 26, which shows the values of
ALT T 1 , G aa G 12 , G 45 G 12 , f 3 f , G aa T 1 , T 1 G 12 , G
aa , G aa ALT .times. G 12 , G aa G 12 + G 45 ##EQU00089##
of all six embodiments, and it is clear that the optical imaging
lens of the present invention satisfy the Equations
(1).about.(9).
[0142] Reference is now made to FIG. 27, which illustrates an
example structural view of a first embodiment of mobile device 20
applying an aforesaid optical imaging lens. The mobile device 20
comprises a housing 21 and an image module 22 positioned in the
housing 21. An example of the mobile device 20 may be, but is not
limited to, a mobile phone.
[0143] As shown in FIG. 27, the image module 22 may comprise an
aforesaid optical imaging lens having five lens elements of the
optical imaging lens, for example the optical imaging lens 1 of the
first embodiment, a lens barrel 23 for positioning the optical
imaging lens 1, a module housing unit 24 for positioning the lens
barrel 23, and an image sensor 171 which is positioned at an image
side of the optical imaging lens 1. The image plane 170 is formed
on the image sensor 171.
[0144] In some example embodiments, the structure of the filtering
unit 160 may be omitted or replaced by coating on each lens
element. In some example embodiments, the housing 21, the lens
barrel 23, and/or the module housing unit 24 may be integrated into
a single component or assembled by multiple components. In some
example embodiments, the image sensor 171 used in the present
embodiment is directly attached to the substrate 172 in the form of
a chip on board (COB) package, and such package is different from
traditional chip scale packages (CSP) since COB package does not
require a cover glass before the image sensor 171 in the optical
imaging lens 1. Aforesaid exemplary embodiments are not limited to
this package type and could be selectively incorporated in other
described embodiments.
[0145] In some example embodiments, the five lens elements 110,
120, 130, 140, 150 having refractive power are disposed inside the
lens barrel 23 and spaced apart with air gaps therebetween.
[0146] In an embodiment, the module housing unit 24 comprises a
lens backseat 2401 and an image sensor backseat 2406 disposed
between the lens backseat 2401 and the image sensor 171. The lens
barrel 23 and the lens backseat 2401 are disposed along an axis
II', and the lens barrel 23 is disposed inside the lens backseat
2401.
[0147] Because the length of the optical imaging lens 1 is merely
3.68 mm, the size of the mobile device 20 may be quite small.
Therefore, the present invention meets the market demand for
smaller sized product designs, and maintains good optical
characteristics and image quality. Accordingly, the present
invention described herein not only reduces the amount of raw
material for the lens housing and obtain economic benefits, but it
also meets smaller sized product design trend and consumer
demand.
[0148] Reference is now made to FIG. 28, which shows another
structural view of a second embodiment of mobile device 20'
applying the aforesaid optical imaging lens 1. One difference
between the mobile device 20' and the mobile device 20 may be the
module housing unit 24 further comprising a first lens seat 2402, a
second lens seat 2403, a coil 2404, and a magnetic unit 2405. The
first lens seat 2402, which is close to the outside of the lens
barrel 23, and the lens barrel 23 are positioned along an axis II'.
The second lens seat 2403 is positioned along the axis II' and
around the outside of the first lens seat 2402. The coil 2404 is
positioned between the outside of the first lens seat 2402 and the
inside of the second lens seat 2403. The magnetic unit 2405 is
positioned between the outside of the coil 2404 and the inside of
the second lens seat 2403.
[0149] The lens barrel 23 and the optical imaging lens 1 disposed
therein are driven by the first lens seat 2402 to move along the
axis II'. The image sensor backseat 2406 is close to the second
lens seat 2403. The filtering unit 160, for example an IR cut
filter, is disposed on the image sensor backseat 2406. The rest
structure of the mobile device 20' is similar to the mobile device
20.
[0150] Similarly, because the length of the optical imaging lens 1
is shortened (e.g., 3.68 mm), the mobile device 20' may be designed
with a smaller size while maintaining good optical performance.
Therefore, the present invention meets the market demand for
smaller sized product designs, and maintains good optical
characteristics and image quality. Accordingly, the present
invention not only reduces the amount of raw material amount for
lens housings and provide economic benefits, but it also meets
smaller sized product design trend and consumer demand.
[0151] According to the above example embodiments, it is clear that
the thickness of a mobile device and the length of an optical
imaging lens thereof can be efficiently reduced through the control
of the ratio between at least one central thickness of lens element
and the sum of all air gaps along the optical axis between five
lens elements in a predetermined range, and incorporated with
detail structure and/or reflection power of the lens elements.
[0152] While various embodiments in accordance with the disclosed
principles have been described above, it should be understood that
they have been presented by way of example only, and are not
limiting. Thus, the breadth and scope of exemplary embodiment(s)
should not be limited by any of the above-described embodiments,
but should be defined only in accordance with the claims and their
equivalents issuing from this disclosure. Furthermore, the above
advantages and features are provided in described embodiments, but
shall not limit the application of such issued claims to processes
and structures accomplishing any or all of the above
advantages.
* * * * *